"""A PEP 517 interface to setuptools
Previously, when a user or a command line tool (let's call it a "frontend")
needed to make a request of setuptools to take a certain action, for
example, generating a list of installation requirements, the frontend would
would call "setup.py egg_info" or "setup.py bdist_wheel" on the command line.
PEP 517 defines a different method of interfacing with setuptools. Rather
than calling "setup.py" directly, the frontend should:
1. Set the current directory to the directory with a setup.py file
2. Import this module into a safe python interpreter (one in which
setuptools can potentially set global variables or crash hard).
3. Call one of the functions defined in PEP 517.
What each function does is defined in PEP 517. However, here is a "casual"
definition of the functions (this definition should not be relied on for
bug reports or API stability):
- `build_wheel`: build a wheel in the folder and return the basename
- `get_requires_for_build_wheel`: get the `setup_requires` to build
- `prepare_metadata_for_build_wheel`: get the `install_requires`
- `build_sdist`: build an sdist in the folder and return the basename
- `get_requires_for_build_sdist`: get the `setup_requires` to build
Again, this is not a formal definition! Just a "taste" of the module.
"""
import os
import sys
import tokenize
import shutil
import contextlib
import setuptools
import distutils
class SetupRequirementsError(BaseException):
def __init__(self, specifiers):
self.specifiers = specifiers
class Distribution(setuptools.dist.Distribution):
def fetch_build_eggs(self, specifiers):
raise SetupRequirementsError(specifiers)
@classmethod
@contextlib.contextmanager
def patch(cls):
"""
Replace
distutils.dist.Distribution with this class
for the duration of this context.
"""
orig = distutils.core.Distribution
distutils.core.Distribution = cls
try:
yield
finally:
distutils.core.Distribution = orig
def _run_setup(setup_script='setup.py'):
# Note that we can reuse our build directory between calls
# Correctness comes first, then optimization later
__file__ = setup_script
__name__ = '__main__'
f = getattr(tokenize, 'open', open)(__file__)
code = f.read().replace('\\r\\n', '\\n')
f.close()
exec(compile(code, __file__, 'exec'), locals())
def _fix_config(config_settings):
config_settings = config_settings or {}
config_settings.setdefault('--global-option', [])
return config_settings
def _get_build_requires(config_settings):
config_settings = _fix_config(config_settings)
requirements = ['setuptools', 'wheel']
sys.argv = sys.argv[:1] + ['egg_info'] + \
config_settings["--global-option"]
try:
with Distribution.patch():
_run_setup()
except SetupRequirementsError as e:
requirements += e.specifiers
return requirements
def _get_immediate_subdirectories(a_dir):
return [name for name in os.listdir(a_dir)
if os.path.isdir(os.path.join(a_dir, name))]
def get_requires_for_build_wheel(config_settings=None):
config_settings = _fix_config(config_settings)
return _get_build_requires(config_settings)
def get_requires_for_build_sdist(config_settings=None):
config_settings = _fix_config(config_settings)
return _get_build_requires(config_settings)
def prepare_metadata_for_build_wheel(metadata_directory, config_settings=None):
sys.argv = sys.argv[:1] + ['dist_info', '--egg-base', metadata_directory]
_run_setup()
dist_info_directory = metadata_directory
while True:
dist_infos = [f for f in os.listdir(dist_info_directory)
if f.endswith('.dist-info')]
if len(dist_infos) == 0 and \
len(_get_immediate_subdirectories(dist_info_directory)) == 1:
dist_info_directory = os.path.join(
dist_info_directory, os.listdir(dist_info_directory)[0])
continue
assert len(dist_infos) == 1
break
# PEP 517 requires that the .dist-info directory be placed in the
# metadata_directory. To comply, we MUST copy the directory to the root
if dist_info_directory != metadata_directory:
shutil.move(
os.path.join(dist_info_directory, dist_infos[0]),
metadata_directory)
shutil.rmtree(dist_info_directory, ignore_errors=True)
return dist_infos[0]
def build_wheel(wheel_directory, config_settings=None,
metadata_directory=None):
config_settings = _fix_config(config_settings)
wheel_directory = os.path.abspath(wheel_directory)
sys.argv = sys.argv[:1] + ['bdist_wheel'] + \
config_settings["--global-option"]
_run_setup()
if wheel_directory != 'dist':
shutil.rmtree(wheel_directory)
shutil.copytree('dist', wheel_directory)
wheels = [f for f in os.listdir(wheel_directory)
if f.endswith('.whl')]
assert len(wheels) == 1
return wheels[0]
def build_sdist(sdist_directory, config_settings=None):
config_settings = _fix_config(config_settings)
sdist_directory = os.path.abspath(sdist_directory)
sys.argv = sys.argv[:1] + ['sdist'] + \
config_settings["--global-option"]
_run_setup()
if sdist_directory != 'dist':
shutil.rmtree(sdist_directory)
shutil.copytree('dist', sdist_directory)
sdists = [f for f in os.listdir(sdist_directory)
if f.endswith('.tar.gz')]
assert len(sdists) == 1
return sdists[0]
